The invention relates to shoe presses for pressing a web of paper or cardboard during its manufacture or treatment. The invention relates more particularly to a shoe press having a shoe support device for reacting forces that act on the press shoe in the machine and/or the cross-machine direction, and to such a shoe support device, wherein the shoe support device includes a first support element affixed to a support stand of the shoe press and having a support surface facing the press shoe, and a second support element in the form of at least one rolling body arranged in a space defined between the support surface of the first support element and an opposite support surface of the press shoe so as to be in contact with the two support surfaces during operation.
A shoe press and shoe support device of the kind described above is known through EP-0 345 501, see FIG. 1. According to this document, the rolling bodies are rotatably journaled on the downstream side of the press shoe and abut a support surface on the fixed support element and an opposite support surface on the press shoe. As the rolling bodies are rotatably journaled on the side of the press shoe, the axis of rotation of each rolling body is always in a fixed position in relation to the press shoe, irrespective of the movement up and down of the press shoe. However, the known construction causes the rolling bodies to become unrotatably jammed between the two support surfaces, especially with the great forces that arise during operation at increased machine speeds. Accordingly, the jamming causes the rolling bodies to slide along the support surface of the fixed support element with consequent friction therebetween.
U.S. Pat. No. 5,650,047 describes a solution to the problem with friction between the press shoe and the fixed support element by arranging spacers in either the fixed support element or the press shoe, which spacers are in the shape of rods, each of which has one end supported on a support surface of the press shoe (alternatively, in the fixed support element) and its other end resting on the bottom of a borehole in the fixed support element (alternatively, in the press shoe), the boreholes having a diameter greater than the rods so that these can follow the radial movements of the press shoe without the support position of the ends of the rods being changed. The present invention solves the friction problem in a way that essentially differs from the known solution in accordance with U.S. Pat. No. 5,650,047.
The object of the present invention is to provide a shoe press, as well as a shoe support device, that utilizes rolling bodies, wherein the tractive forces of the press shoe are transmitted to the fixed support element via the rolling bodies without friction arising between load-transmitting surfaces.
In accordance with the invention, the shoe press, as well as the shoe support device, is characterized in that, when the press shoe is moved relative to the second press element, the at least one rolling body is arranged to roll along the two support surfaces while rotating about an axis of rotation that moves relative to and in the same direction as the press shoe.